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Oct
10
comment Solving Fredholm Equation of the first kind
I defer to the mathematicians in the group, but the Volterra integral equation mentioned in the duplicate question is a Fredholm integral equation of the second kind, and of special convolution form. That equation has an unknown left-hand side which also appears under the integral. The Fredholm integral equation of the first kind in this question has a known left-hand side which does not appear under the integral, and is not explicitly of convolution form. Duplicate?
Oct
9
answered Solving Fredholm Equation of the first kind
Oct
7
awarded  Necromancer
Oct
6
awarded  Necromancer
Sep
23
answered Rotated Rectangles
Sep
18
awarded  Nice Answer
Sep
17
revised Why does Fourier give a shifted frequency?
added 21 characters in body
Sep
9
comment Error computing sum of sum of digits
I really want to use your technique because it is creative thinking plus blinding speed; however, cumDigitSum[12,10] returns 49 ?? I've tried to understand your approach in order to suggest an edit to the code, but as yet cannot.
Sep
9
comment Error computing sum of sum of digits
Hi Daniel: I can't get your function to give the same results as Mr.Wizard's. The "6" in b^6 looks suspicious...
Sep
3
answered How to speed up my Project Euler code
Sep
1
awarded  Yearling
Aug
21
answered To inscribe a circle in a given triangle
Aug
7
comment Why does Fourier give a shifted frequency?
@LeoFang Arbitrary resampling of a signal is not always possible in the real world. Given only the original 201-point signal, tapering removes the problem, as I suggested, as JamesCunnane suggested in a comment (recommending trend removal as well), and as Mr.Wizard suggested in an answer. Again, this does not mean your answer is wrong.
Aug
7
comment Why does Fourier give a shifted frequency?
@LeoFang I'm sorry about your downvote too, especially since you do not say how or why my explanation is wrong. I will not downvote your answer, you could do that yourself because both our explanations are the same, as stated by xslittlegrass in the comment above. You and I both suggest sampling more points to solve the problem. In my case 297 points, in yours 314, a trivial difference caused by the low-amplitude higher-frequency component. Can you see that, for harmonic signals, an incomplete period is the same as mismatched endpoint amplitudes?
Aug
6
answered factorization of integer into two parts with specific prime factors
Aug
6
answered Mathematica's “POV” export format ignores ColorFunction
Aug
5
awarded  Suffrage
Jul
31
revised Why does Fourier give a shifted frequency?
added 1525 characters in body
Jul
30
answered Why does Fourier give a shifted frequency?
Jul
9
answered Conveying density of 5-smooth (Hamming) numbers